CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES Narrative (Details)	May 31, 2020	May 31, 2019
Cash Cash Equivalents And Short Term Investments [Abstract]
Percentage of marketable securities investments mature within one year	99.00%	33.00%
Percentage of marketable securities investments mature within one to four years	1.00%	67.00%

Percentage of marketable securities investments mature within one to four years.

No definition available.

Name:	orcl_PercentageOfMarketableSecuritiesInvestmentsMatureWithinOneToFourYears
Namespace Prefix:	orcl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant